This is an open label, randomized, multiple dose study to quantify the amount of Nonoxynol-9 (N-9) retained in the vagina at selected timepoints after instillation. Five different formulations will be studied (foam, 2 types of gel, cellophane, and suppository). For each formulation studied, at least 4 timepoints of retention (2 hr, 4 hr, 8 hr, and 12 hrs) will be studied. For the Advantage gel formulation, a 24 hour timepoint will also be studied. Each subject will be randomly assigned to receive the total series of instillations for one of the product formulations. For each product, a subject will be expected to complete 4 (or 5) instillations, one instillation for each assigned timepoint. At each study visit (separated by at least 5 days) , ONE of the selected timepoints will be studied. Each woman will undergo a vaginal lavage at the randomly assigned timepoint during the study visit. For each subject, the order that the time points are studied will be randomly assigned. Recent estimates suggest that over 75% of the 10-12 million HIV-infected adults worldwide have contracted the virus through heterosexual intercourse (1) . As of June 1992, heterosexual transmission became the primary mode of transmission of HIV to women in the United States (2). Currently, changes in sexual behavior and use of barrier contraception are the only ways to reduce the rate of heterosexual and homosexual (male to male) spread of these infections. In fact, male condoms, when used consistently and regularly, have been proven effective to prevent pregnancy (3), Human Immunodeficiency Virus (HIV) (4-6) and other sexually transmitted diseases (STDS) (7) and are recommended by the Public Health Service for use to prevent heterosexual transmission of HIV (8). However, it is important that every individual have a method he or she can use as personal protection against STDS, including HIV (9). To date 90% of clinical visits are completed and 80% of sample analysis has occurred. We anticipate completion/analysis May of 1997.